The gd version shipped with RH 6.2 is 1.3.6 which is very old. This makes use of newer code using the new gd versions difficult. Bug 0076 (http://bugzilla.redhat.com/bugzilla/show_bug.cgi?id=9976) shows that the reasoning behind the version hitch is linuxconf, hence the bugzilla entry against linuxconf :-) Can linuxconf be updated to the new gd API for next release.
This is already fixed in Raw Hide (ftp://ftp.redhat.com/pub/rawhide/), which is built from our development tree. We're currently using gd 1.8.2 for development on our next release.